**Next message:**Frederik Orellana: "Re: Problem using OneLoop"**Previous message:**valer zetocha: "Euclidean metric?"**In reply to:**Peter Blunden: "Problem using OneLoop"**Next in thread:**Frederik Orellana: "Re: Problem using OneLoop"**Reply:**Frederik Orellana: "Re: Problem using OneLoop"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

Hello.

I tried to reproduce this behaviour. An integrand corresponding to what

you write would be:

amp = Pair[Momentum[k], Momentum[p1]]FeynAmpDenominator[

PropagatorDenominator[k, lam], PropagatorDenominator[(k - q), lam],

PropagatorDenominator[(k - p1), m], PropagatorDenominator[(k +

p2), M]];

With this,

OneLoop[k, amp]

evaluates without problems.

I need more details in order to help: Your integrand in FeynCalc

notation; the version of FeynCalc you're using.

Frederik

Peter Blunden wrote:

*> I'm trying to do an integral that FeynCalc chokes on. The message returned
*

*> is the usual
*

*>
*

*> FYI: Tensor integrals of rank higher than 3 encountered; Please use the
*

*> option CancelQP -> True or OneLoopSimplify->True or use another program.
*

*>
*

*> However, it appears that CancelQP->True is the default, and OneLoopSimplify
*

*> expresses the results in terms of Contract3, which doesn't seem to exist.
*

*>
*

*> The integrals are box diagrams, and a typical term would look something like
*

*>
*

*> (k.p1)^3 / [k^2-lam^2][(k-q)^2-lam^2][(k-p1)^2-m^2][(k+p2)^2-M^2]
*

*>
*

*> where p1^2=m^2 and p2^2=M^2. This term looks innocent enough, and in fact
*

*> looks to me like it IS of rank 3. By a lot of fudging and manipulating I
*

*> managed to get a result using ScalarProductCancel, but it is hit and miss
*

*> for various terms in the amplitude.
*

*>
*

*> Is there a fix in FeynCalc, or do I have to use another program (and if so,
*

*> which one)?
*

**Next message:**Frederik Orellana: "Re: Problem using OneLoop"**Previous message:**valer zetocha: "Euclidean metric?"**In reply to:**Peter Blunden: "Problem using OneLoop"**Next in thread:**Frederik Orellana: "Re: Problem using OneLoop"**Reply:**Frederik Orellana: "Re: Problem using OneLoop"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Mail actions:**[ respond to this message ] [ mail a new topic ]

*
This archive was generated by hypermail 2b29
: 08/18/18-09:00:01 AM Z CEST
*